Electrooxidation of sulfanilamide and its voltammetric determination in pharmaceutical formulation,human urine and serum on glassy carbon electrode

For the first time, sulfanilamide(SFD) was determined in otologic solution, human urine and serum by electroanalytical techniques on glassy carbon electrode(GCE). The cyclic voltammetry(CV) experiments showed an irreversible oxidation peak at t 1.06 V in 0.1 mol/L BRBS(p H ? 2.0) at 50 m V/s. Different voltammetric scan rates(from 10 to 250 m V/s) suggested that the oxidation of SFD on the GCE was a diffusioncontrolled process. Square-wave voltammetry(SWV) method under optimized conditions showed a linear response to SFD from 5.0 to 74.7 μmol/L(R ? 0.999) with detection and quantification limits of 0.92 and3.10 μmol/L, respectively. The developed SWV method showed better results for detection limit and linear range than the chronoamperometry method. It has been successfully applied to determine SFD concentration in pharmaceutical formulation, human urine and serum samples with recovery close to 100%.

Synthesis of Sulfanilamide Derivatives of BISA

Ebselen was selected as the lead compound and a series of derivatives of benzisoselenazolone was designed and synthesized with pharmacological interest. Under ether water NaHCO 3 reaction system, 2 chloroselenobenzoyl chloride was treated with a series of sulfanilamide and ten Ebselen derivatives with SO 2NHR group attached to the p position of 2 phenyl moiety were prepared in good yields. All these new conpounds were characterized by 1H NMR, IR, UV spectra and elemental analysis.

Synthesis,Crystal Structure and Fluorescent Property of a New Sulfanilamide Schiff-base Compound

A new sulfanilamide Schiff-base compound N,N -（p-phenyl sulfanilamide）-5,6-dimethoxy-pyrimidine-（2-hydroxyl benzene） methylidene has been synthesized by the condensation of equimolar salicylaldehyde and 4-（p-amino phenyl sulfanilamide）-5,6-dimethoxy-pyrimidine in an anhydrous ethanol solution.The compound was characterized by elemental analysis,IR spectra,and single-crystal X-ray diffraction.The crystal belongs to the monoclinic system,space group P21/c with a=19.0425（11）,b=11.1914（6）,c=9.0075（5）,β=93.9650（10）°,Z= 4, V= 1915.01（18） A3,Dc = 1.437 g/cm^3, Mr = 414.43, λ（MoKa） = 0.71073 A,μ= 2.09 mm^-1, F（000） = 864, R = 0.0385 and wR = 0.1224.

Monitoring real time polymorphic transformation of sulfanilamide by diffuse reflectance visible spectroscopy

This study investigated the development of a novel approach to surface characterization of drug poly- morphism and the extension of the capabilities of this method to perform ＇real time＇ in situ measure- ments. This was achieved using diffuse reflectance visible （DRV） spectroscopy and dye deposition, using the pH sensitive dye, thymol blue （TB）. Two polymorphs, SFN-β and SFN-γ, of the drug substance sulfanilamide （SFN） were examined. The interaction of adsorbed dye with polymorphs showed different behavior, and thus reported different DRV spectra. Consideration of the acid/base properties of the morphological forms of the drug molecule provided a rationalization of the mechanism of differential coloration by indicator dyes. The kinetics of the polymorphic transformation of SFN polymorphs was monitored using treatment with TB dye and DRV spectroscopy. The thermally-induced transformation fitted a first-order solid-state kinetic model （R2=0.992）, giving a rate constant of 2.43 × 10^- 2 s 1.

Design, Synthesis and Characterization of Novel Sulfonamides Derivatives as Anticancer Agent Targeting EGFR TK, and Development of New Methods of Synthesis by Microwave Irradiation

Some novel sulfonamide-derivatives were designed to develop novel kinase inhibitors. The molecular docking study was performed for the designed compounds against epidermal growth factor kinase receptor T790M/L858R (TMLR) (PDB ID: 5EDQ) to identify new drug candidates for treating cancer. Binding free energy was calculated by Molegro virtual docker (MVD) to select the most promising hits. The corresponding docking score values into EGFR (TMLR) of 4b gave the best energy docking -147.213 Kcal/mol. And some of the designed sulfonamide derivatives have been synthesized by conventional method in addition to a microwave-assisted method of synthesis. The reaction of an amino group-containing drug;sulfamethoxazole and sulfanilamide with carbonyl group in benzoyl chloride and phthalic acid in basic media, generated a series of sulfonamide derivatives. The structures of all the synthesized compounds were well characterized by Mass spectrometry (MS), Infrared spectroscopy (IR), 1H nuclear magnetic resonance (1H NMR), 13C nuclear magnetic resonance (13C NMR) and elemental analysis. After obtaining experimental data regarding the yield and the time taken for the synthesis by both the approaches, conventional and microwave-assisted method, it was shown that the microwave-assisted method gave higher yield with shorter time and higher temperature compared to conventional heating methods.

Synthesis, Characteristic and Antimicrobial Activity of Some New Spiro[indol-thiazolidon-2,4-diones] and Bis(5-fluorospiro[indoline-3,2’-thiazolidine]-2,4’-dione) Probes

In a search for new antimicrobial agents, some new spiro[indol-thiazolidon- 2,4-diones] (6a-c) were synthesized by condensation of 5-substituted isatins 1 with sulfanilamide in MeOH, followed by aroylation with p-nitrobenzoyl chloride in DMF to get compounds 4a-c. Cycloaddition of 4a-c with thioglycolic acid in a dry non-polar solvent (dioxane) gave the targets 6a-c. Also, bis(5-fluorospiro[indoline-3,2’-thiazolidine]-2,4’-dione) (9) was synthesized by condensation of 5-fluoroindoline-2,3-dione with benzene-1,4-diamine (2:1 by mol) in MeOH, which followed by cycloaddition with thioglycolic acid in dioxane gave compound 8. Acylation of the later with 2,2,2-trifluoroacetic anhydride in THF has yielded the target 9. Structures of the products have been deduced from their elemental analysis and spectral data. The in vitro antimicrobial activity of the new systems 6a-c, and 9 was tested.

NitroMAC：An instrument for the measurement of HONO and intercomparison with a long-path absorption photometer

Nitro MAC（French acronym for continuous atmospheric measurements of nitrogenous compounds） is an instrument which has been developed for the semi-continuous measurement of atmospheric nitrous acid（HONO）. This instrument relies on wet chemical sampling and detection using high performance liquid chromatography（HPLC）-visible absorption at540 nm. Sampling proceeds by dissolution of gaseous HONO in a phosphate buffer solution followed by derivatization with sulfanilamide/N-（1-naphthyl）-ethylenediamine. The performance of this instrument was found to be as follows： a detection limit of around 3 ppt with measurement uncertainty of 10% over an analysis time of 10 min. Intercomparison was made between the instrument and a long-path absorption photometer（LOPAP） during two experiments in different environments. First, air was sampled in a smog chamber with concentrations up to 18 ppb of nitrous acid. Nitro MAC and LOPAP measurements showed very good agreement. Then, in a second experiment, ambient air with HONO concentrations below250 ppt was sampled. While Nitro MAC showed its capability of measuring HONO in moderate and highly polluted environments, the intercomparison results in ambient air highlighted that corrections must be made for minor interferences when low concentrations are measured.